Indeed, if the current campaign goes on much longer and the Israelis launch a major ground invasion of Gaza as they now appear to be preparing to do, Obama could face a major international crisis  comparable to Israel’s failed 2006 war against Lebanon’s Hezbollah  just as he takes office in three weeks’ time.

"With this assault, the fallout has already started to spread considerably beyond the constituency of people who are Palestinians," noted Helena Cobban, a veteran Middle East analyst, who cited popular protests in Egypt, Jordan, and elsewhere in the Arab world since the Israeli campaign began Saturday.

"It has already started, and we can confidently expect that the longer Israel’s assault is maintained, the higher the regional stakes will rise."

The Israeli attacks, which came a week after the expiration of an increasingly shaky six-month cease-fire, have so far reportedly killed more than 300 Palestinians, while two Israelis have died in rocket attacks launched from Gaza.

While Israeli Defense Minister Ehud Barak initially insisted that Israel’s war aims were designed to reinstate and strengthen the cease-fire, the former prime minister, who hopes to reclaim that post as head of the Labor Party in Feb. 10 elections, appeared to broaden them in a speech to the parliament Monday in which he pledged "war to the bitter end" against Hamas, the Islamist party that controls Gaza. Deputy Prime Minister Haim Ramon said Israel aimed to "topple Hamas."

As with the 2006 war, the administration of President George W. Bush has offered strong backing for the Israeli attack, demanding that Hamas stop firing rockets into Israel and agree to a "sustainable and durable cease-fire."

"The United States understands that Israel needs to take actions to defend itself," said White House spokesman Gordon Johndroe at Bush’s ranch in Texas, where the outgoing president is spending the Christmas holiday. Johndroe called the leadership of Hamas "nothing but thugs" during a briefing on Sunday.

Meanwhile, Obama, who is vacationing in Hawaii, has declined to comment on the violence and the threat of larger crisis. "The fact is that there is only one president at a time, and that president now is George Bush," Obama’s top political adviser, David Axelrod, said on a nationally televised public-affairs program Sunday.

Axelrod went on to quote Obama as defending Israel’s retaliation against Gaza-based militants who launched rockets into the southern Israeli town of Sderot when he visited there in July.

"If somebody was sending rockets into my house, where my two daughters sleep at night, I’m going to do everything in my power to stop that. And I would expect Israelis to do the same thing," Obama had said at the time. In his speech to the Knesset Monday, Barak significantly repeated the quotation in defending Israel’s action.

During the presidential campaign, Obama repeatedly insisted that he  in contrast to his predecessor  would make Israeli-Palestinian peace negotiations a top priority "from day one" in his administration. He reiterated his intention explicitly when he introduced the senior members of his foreign-policy team in Chicago earlier this month.

A number of Obama’s informal advisers  including former national security advisers Brent Scowcroft and Zbigniew Brzezinski  have publicly urged the president-elect to follow through on that commitment, arguing that nothing could do more to help Washington recover its badly damaged credibility in the Arab and Islamic worlds than to lead a major effort at achieving a two-state solution.

But such an effort is now seen as increasingly problematic, particularly if the Gaza conflict escalates further, according to most experts.

"It clearly, clearly complicates any effort to engage in a vigorous diplomatic effort, because the Israeli operation in the Gaza Strip has necessarily weakened [Palestine Authority President] Mahmoud Abbas and his efforts to negotiate with the Israelis," said Steven Cook, a Middle East analyst at the Council on Foreign Relations, who also noted the conflict also created "an untenable situation for the Syrians to continue" their Turkish-mediated peace talks with Israel.

The violence "is going to make an already dramatically complicated situation worse," Aaron Miller, a former senior U.S. state department Middle East negotiator now at the Woodrow Wilson Center for International Scholars, told the Wall Street Journal. "Obama’s going to inherit a crisis without the capacity to do much about it," he told Politico.com.

Not everyone is so pessimistic, however. Daniel Levy, a former Israeli peace negotiator currently based at the New America Foundation and the Century Fund, noted that the current crisis serves as a reminder that the Israeli- Palestinian conflict cannot be ignored.

"[These] events should be ‘Exhibit A’ in why the next U.S. government cannot leave the Israeli-Palestinian conflict to fester or try to ‘manage’ it  as long as it remains unresolved, it has a nasty habit of forcing itself onto the agenda," he wrote on his blog.

"The new administration needs to embark upon a course of forceful regional diplomacy that breaks fundamentally from past efforts," he added, noting that a consensus within the foreign policy establishment has emerged in favor of a more assertive peacemaking role, including setting forth the basic elements of final settlement, as laid out by Brzezinski and Scowcroft, among other major players.

Cook also agreed that Obama’s decisive electoral victory and his vision of more aggressive Middle Eastern diplomacy will give him more leverage over the Israelis who "aren’t looking for a fight with" with the new president.

Still, the ongoing violence makes it "hard to see any scenario which produces remotely positive results for anyone involved," according to Marc Lynch, a professor at George Washington University who specializes in Arab media and public opinion.

"A bloody retaliation against Israelis seems highly likely, and if Abbas is seen as supporting the Israeli offensive against his political rivals, then Hamas may well emerge from this even stronger within Palestinian politics," he wrote on his widely read blog. "The offensive is highly unlikely to get rid of Hamas, but it will likely leave an even more poisoned, polarized and toxic regional environment for a new president who had pledged to re-engage with the peace process."

Lynch and Cook, among others, also believe that the continued fighting in Gaza will reopen and widen the breach  already made clear during the 2006 Israel-Hezbollah war between Arab regime allied to the U.S. and their own publics  to the benefit of Iran and its regional allies, not to mention radical Sunni forces, including al-Qaeda.

The fact that Hezbollah chief Hassan Nasrallah called Monday for Arabs and Muslims to launch "uprisings" in support of Gaza "should be cause for concern," according to Cook, who noted that the catalyst for the 2006 war was an attack on an Israeli patrol designed to divert the Israelis from ongoing military operations in Gaza.

"Obama has scrupulously [and wisely] adhered to the ‘one president at a time’ formula in foreign policy up to this point," Lynch wrote, "but you have to wonder how long he can sit by and watch the prospects for meaningful change in the region battered while the administration sits by and cheers."